This invention relates to semiconductor switching circuits and, more particularly, to a semiconductor switching circuit which converts a light signal into an electrical signal by means of a photovoltaic diode array optically coupled to such light emitting element as a light emitting diode which converts an input signal into the light signal, the converted electrical signal being utilized for driving such output means as FET, preferably a metal-oxide-semiconductor field effect transistor (which shall be hereinafter referred to simply as "MOSFET").